Off-the-Shelf Power Supply-Based Battery/Supercapacitor Emulator for Charger Functionality Testing

This paper presents a method of battery/supercapacitor emulator (BSE) rapid prototyping, based on modified off-the-shelf components. Low-cost commercial constant output voltage switching power supply, transformed into an input-voltage-controlled converter, is utilized as emulator power stage. The control over input voltage of the power supply is gained by appropriately altering the voltage feedback branch of the control circuitry. Consequently, it becomes possible to tightly regulate the input voltage of the device according to a predefined current-voltage relation and hence emulate any static and/or dynamic behavior by sensing the input current of the power supply and varying its input voltage appropriately. For battery or supercapacitor emulation, the desired charging characteristics may be either derived from manufacturer provided datasheet, obtained experimentally or estimated by solving the appropriate electrical equivalent circuit of the emulated storage device. In order to demonstrate the validity of the proposed method, a prototype was designed and built using an off-the-shelf boost dc-dc converter-based low-cost power supply. Dynamic input characteristics of the prototype were experimentally evaluated and two commercial storage devices (namely MR-2791 lithium ion battery and Maxwell BMOD0058-E016-B02 supercapacitor packs) charging sequences were emulated. The resulting I-V input relations were shown to closely resemble the charging behavior of real devices.